Mount Parnitha rises north of Athens, about 30 kilometres from the city centre. Its highest point, Karavola, is 1,413 metres high, which makes Parnitha the highest mountain in Attica. The second peak, Ornio, reaches about 1,350 metres. Both summits hold military installations and antennas, so walkers cannot reach them.

The mountain covers about 250 square kilometres. It is the highest of the mountains around the plain of Athens, which also include Mount Penteli and Mount Hymettus. Much of it is limestone, with rocky slopes, ravines and a number of springs. In winter, snow usually lies above 1,000 metres for several weeks.

The upper part of the mountain is a national park, created in 1961. Its core covers about 38 square kilometres. Barriers close some forest roads inside the core to private cars, to protect the animals and plants.

Marked paths cross Parnitha from several starting points around the mountain. A well-known one climbs the Houni ravine from Thrakomakedones, a suburb at the foot of the mountain. It is about four and a half kilometres long and takes about two and a half hours, with a steady climb all the way.

There are two mountain refuges, both at about 1,160 metres. Bafi is the larger one, and a road reaches it. Flambouri stands on a ridge above Thrakomakedones and is reached only on foot. An easy marked path of about three and a half kilometres joins the two in a little over an hour. Both refuges offer food and beds, so check that they are open and book a bed before you go.

Parnitha is also a place for sport climbing. Several crags above the village of Fyli, on the western side of the mountain, have bolted routes. One of them, Pano Alogopetra, has more than thirty.

Two kinds of forest cover Parnitha. Aleppo pine grows on the lower slopes, up to about 1,000 metres. Above that height stands a forest of Greek fir. More than 800 plant species have been recorded on the mountain, and a few of them grow nowhere else. Wild peonies, tulips and orchids are among the plants of the mountain.

Fire has burned large parts of Parnitha more than once since 2007. The fire of that year alone burned about 56 square kilometres. A visitor walks through both living forest and burned slopes.

Red deer live on the mountain. Wolves returned to Parnitha around 2010, and the deer have become far fewer since then, so you may not see one. On the foothills near the village of Afidnes lies Lake Beletsi, a small artificial lake made in the 1970s. It has picnic tables and a playground beside it, and ducks and turtles live in the water.

The fortress of Phyle stands on the western slopes, above the village of Fyli. It was built in the 4th century BC to guard the pass from Thebes to Attica, and parts of its stone walls still stand. Entry is free. In 404 BC the Athenian general Thrasybulus seized Phyle and began there his fight against the Thirty Tyrants, the rulers of Athens.

The Cave of Pan is on the same side of the mountain, at about 700 metres. About 2,000 ancient lamps, left there as offerings, were found in it. A marked path leads down to the Goura gorge and up to the cave in about an hour. The last part is steep, and inside you need a helmet and a strong torch.

On the lower slopes near the settlement of Varympompi is Tatoi, the former estate of the Greek royal family. Its forest holds about forty buildings, a palace and a royal cemetery among them. Check which are open.